On my 1993SE Maxima, the previous owner had thrown away the old Bose head unit and installed an after market one. A friend told me that the speakers perform much better with the actual Bose unit, so I installed the one without the CD (cassette player only), after unsuccessfully searching for the one with the CD and the cassette.

Questions:
1. Is the Bose system really necessary to improve speaker life and performance ?
2. Where can I get the one with the CD/cassette ? I tried junkyards, but the one they had didn't work. I don't want to buy it from a dealer. Can you guys recommend an inexpensive place ?
3. The system with the cassette doesn't give as good bass, treble, balance and fade adjustment as the one with the CD player. Any suggestions on how I can adjust these with the cassette player ?

thanks,
Ninjarider